N-(2-hydroxyhydrocarbonyl) iminodicarboxylates

ABSTRACT

Novel N-(hydroxyhydrocarbyl) iminodicarboxylates or the corresponding carboxylic acids are of the formula:   WHEREIN R1 is an aliphatic hydrocarbon radical of 4 to 20 carbon atoms, R2 and R3 are divalent aliphatic or aromatic hydrocarbon radicals of 1 to 9 carbon atoms and X and Y are either hydrogen or salt-forming elements or radicals. In preferred embodiments of the invention, R1 is a saturated radical of 12 to 20 carbon atoms, R2 and R3 are identical alkylene radicals of 1 to 2 carbon atoms, and X and Y are the same monovalent metals, or lower alkanolamines e.g., sodium, triethanolamine. The novel compounds are surface active and substantive to fibrous materials such as cotton, wool and synthetics. They are useful as detergents or as components of detergent compositions. Preferred compounds function very effectively as softening agents, either alone or in conjunction with other detergent composition materials. Additionally, they may be used as starting materials for the manufacture of corresponding N-oxides, which also may be employed as detergents and textile softeners.

United States Patent 1 Sundby et al.

[451 Apr. 3, 1973 [54] N-(2-HYDROXYHYDROCARBONYL) IMINODICARBOXYLATES [75] Inventors: Bjorn Sundby, Piscataway; Edward J. Kenney, Bernardsville; Harold E. Wixon, New Brunswick, all of NJ.

[73] Assignee: Colgate-Palmolive Company, New

York, NY.

[22] Filed: Nov. 28, 1969 [21] Appl. No.: 880,992

[52] US. Cl. ..260/534 E, 252/8.8, 252/117, 252/546, 260/50l.1l, 260/519 [51] Int. Cl ..C07c 101/20 [58] Field of Search ..260/534 E, 534 M, 501.11; 252/l52,l37, 117, 8.8

[56] References Cited UNITED STATES PATENTS 2,891,053 6/1959 Meyer et al. ..260/534 E 3,398,097 8/1968 Kersnar et al. ..252/152 2,930,761 3/1960 Charret ..252/152 2,368,604 1/1945 White ....260/534 E 2,401,196 5/1946 Senkus..... ...260/534 E 2,816,920 12/1957 Andersen ..260/534 E OTHER PUBLICATIONS Pascal, Chem. Abst. 55 273221 (1961) lsraily, ibid. 65 3306g (1966) I-Iirte et al., ibid 60 5756f Dyatlova et al. ibid 62 7355b (1965) Primary Examiner- Lorraine A. Weinberger Assistant Examiner-John F. Terapane Att0rneyI-Ierbert S. Sylvester, Murray M. Grill, Norman Blumenkopf, Ronald S. Cornell, Thomas J. Corum, Richard N. Miller and Robert L. Stone [57] ABSTRACT Novel N-(hydroxyhydrocarbyl) iminodicarboxylates or the corresponding carboxylic acids are of the formula:

The novel compounds are surface active and substantive to fibrous materials such as cotton, wool and synthetics. They are useful as detergents or as components of detergent compositions. Preferred compounds function very effectively as softening agents, either alone or in conjunction with other detergent composition materials. Additionally, they may be used as starting materials for the manufacture of corresponding N-oxldes, whichalso may be employed as detergents and textile softeners.

5 Claims, No Drawings 1 N-(2-HYDROXYHYDROCARBONYL) IMINODICARBOXYLATES This invention relates to novel N-(Z-hydroxyhydrocarbyl) iminodicarboxylates and the corresponding iminodicarboxylic acids. It has been discovered that these compounds are useful surface active agents and are substantive to a variety of fibrous materials. Thus, they may be used as emulsifiers, solubilizing agents for lipophilic materials, wetting agents, detergents and softeners for textiles. They are also useful as reagents from which the corresponding N-oxides may be made, which oxides also possess surface active and textile-substantive properties.

Since the introduction of commercial synthetic organic detergents and emulsifiers to replace the conventional water-soluble higher fatty acid soaps, much research work has been performed in an effort to improve such compounds and compositions including them, with the object of obtaining better and more convenient laundering of textiles. As a result, a wide variety of types of surface active agents and detergents has been produced and many such compositions have been manufactured commercially and have been introduced to the market place. As better products were made, the goals set for researchers on detergency were increased and the properties of the desired products were such as to have been thought impossible of attainment only a few years before. For one thing, although the cleaning function of surface active materials is still very important and products which clean better than competitive compounds are always in demand, additional functions of cleaning compositions and compounds were desired. For example, with the increasing importance of cold water washing, detergent compositions were desired which would be capable of successfully cleaning and whitening textiles and laundry in cold water, as well as in hot water. Such washing capability is of importance in making a product acceptable for the washing of wool and and other shrinksensitive materials. As softening agents have been introduced, consumers have accepted them and have wanted them to be easier to use than has been the case in the past. Although there is still a strong market for textile softeners which are applied in the final rinse of a washing cycle, many housewives object to having to be present to add the softener to the washing machine at that time and relatively few washing machines include devices for addition of softeners in the final rinse. Therefore, more effective softeners have been in demand, which would be capable of being added to the wash water as a part of the detergent composition and would not require a separate addition to the rinse.

The present invented compounds are useful surface active agents. They possess detergent activity in both hard and soft waters and at both elevated and lower temperatures. In addition, preferred compounds are excellent in textile softening activity, even when used in the washing, rather than the rinsing step of a laundering operation. Such an activity evidences a high degree of substantivity, which is unexpected in a surface active material which itself functions to release adsorbed and absorbed substances from materials being washed. The compounds are also generally capable of making washed textiles and other articles anti-static. Additionally they are usually desirably low-foaming in wash water.

In accordance with the present invention, there are provided novel compounds of a formula,

which are effective detergents and which preferably also serve to soften fibrous materials when applied to them, as in aqueous solution. In the formula, R is an aliphatic hydrocarbon radical of 4 to 20 carbon atoms, R and R are divalent, aliphatic or aromatic hydrocarbon radicals of l to 9 carbon atoms and X and Y are hydrogen or a salt-forming element or radical. R and R may be the same or different and X and Y may be the same or different. If either X or Y is an element, it is preferred that it should be an alkali metal, an alkaline earth metal or other suitable salbforming metal, capable of making the compounds water soluble. If X or Y is a radical, it is preferred that such be ammonium, alkylamine or alkanolamine, either mono-, di-, or tri-alkylamine or mono-, dior tri-alkanolamine, in which the alkyl and alkanol groups of the salt-forming amines are of l to 4 carbon atoms, preferably 2 to 3 carbon atoms.

e In preferred embodiments of the invention, the compounds are those wherein R is an aliphatic hydrocarbon radical of 12 to 20 carbon atoms, R and R are aliphatic alkylene radicals of l to 2 carbon atoms, and X and Y are monovalent salt-forming ions, including alkali metal, ammonium, mono-, diand tri-alkylamine and mono-, diand tri-alkanolamine. In such preferred compounds, it is additionally preferred that R and R are the same and that X and Y are the same.

With respect to X and Y, it will be noted that in the above formula there has been no allowance made for divalent or polyvalent salt-forming ions. Nevertheless, it may be considered that X and Y stand for a monovalent portion of any salt-forming ion. Thus, if a divalent ion, such as magnesium, is employed, it could be joined to both the carboxylic groups of the present compounds or could be joined to only one of them, with another valence bond either otherwise tied up, as with a different anion, or with it joined to the carboxylic groups of different iminodicarboxylic acids. In such a way, mixed salts may be formed,'as may be acid-salt compounds.

The preferred compounds mentioned above are found to be excellent as textile softeners, especiallyfor cotton articles, which may be washed with them, even in the presence of builders, other deters'ive compounds and additives. They may be used in normal washing, including rinsing operations. With respect to such softening properties, the most preferred compounds are the salts of N-(2-hydroxy-higher alkyl) iminodi-lower carboxylic acids, wherein the higher alkyl is of 14 to 22 carbon atoms and is of straight chain structure. Of such compounds, it is preferred to employ the sodium and potassium salts, with the sodium salt being that which is generally considered most useful. Of the lower carboxylic acids, the most preferred is acetic acid, so that the most preferred of these compounds are the N-(2- other compounds within the scope of the present invention are also useful surface active agents, wetting agents, emulsifiers and detergents, but might not produce to the same extent the extremely desirable softening activity shown by the most preferred compounds of this invention. In fact, in some instances such compounds might be essentially ineffective as practical softeners, although they will often have the unexpected advantage of being highly useful for their detergency or other surface active properties, often in both hard and soft waters, and at elevated or comparatively low washing temperatures.

Among compounds within the scope of the formulas previously given are N-(2-hydroxy-n-hexyl)- iminodiacetic acid, mono-n-propanolamine salt; N- (2- hydroxy-n-heptyl)-iminodiacetic acid, ditriethanolamine salt; N-(2-hydroxy-n-octyl)- iminodiacetic acid, disodium salt; N-(Z-hydroxypropylene tetramer)-iminodiacetic acid, dipotassium salt; N-(2-hydroxydodecyl)-iminodipropionic acid, dilithium salt; N-(Z-hydroxy-propylene pentamer)- iminodiacetic acid, magnesium salt; N-(Z-hydroxyhexadecyl)-iminodiacetic acid, disodium salt; N-(2- hydroxydocosyl)-iminodiacetic acid, disodium salt; N- (2-hydroxytetradecyl)-iminodiacetic acid; N-(2- hydroxyoctadecyl)-iminodiacetic acid; N-(Z-hydroxyn-hexyl)-iminodi-n-propionic acid, monopotassium salt; N-(2-hydroxy-6- ethyl-n-decyl)-iminodi-n-butyric acid, di-diethanolamine salt; N-(2-hydroxydodecyl)- iminodi-p-benzoic acid, magnesium salt; N-( 2-hydroxyhexadecyl)-iminoacetic-propionic acid, calcium salt; N-(2-hydroxyoctadecenyl)Jminobenzoic-toluic acid, diisopropylamine salt; N-(2-hydroxyoctadecyl)- iminodipentanoic acid, mixed sodium and potassium salt; N-(2-hydroxytetradecyl)Jminodiacetic acid, monoammonium salt; N-(2-hydroxyhexadecyl)- iminopropionic-butyric acid, mono-monoethanolamine salt; N-(2-hydroxytetradecyl)-iminobenzoic-o-isopropylbenzoic acid, mixed magnesium and calcium salt; N- (Z-hydroxyoctadecyl)-iminoacetic-toluic acid, mixed sodium and triethanolamine salt; N-(Z-hydroxydocosyl)-iminodiacetic acid, aluminum salt; N-(2- hydroxy-mixed higher linear alkyl of 14-16 carbon atoms)-iminodiacetic acid, disodium salt; N-( 2-hydroxy-n-tetradecyl)-iminodi-n-decanoic acid, disodium salt; and N-(2-hydroxyoctadecyl)-imino-n-pentanoic-nheptanoic acid, mixed sodium and potassium salts.

The above-mentioned compounds are only illustrative of those within the formulas previously given and it will be clear that other compounds within the scope of such formulas are also useful and in many cases may possess properties superior to those specifically listed above. Thus, variations may be made in the above specific compounds, wherein other mentioned constituents are employed to replace those illustrated. In some cases, additional non-interfering substituents may be employed and usually these will be present on the longer chain portions of the molecules, such as on the R group, where they do not as significantly affect the properties of the final product. Among useful substituents are amino, hydroxy, halogen, e.g., chlorine, bromine, fluorine, and hydroxy-lower alkyl, wherein the alkyl is of up to four carbon atoms. The number of such substituents present will usually be small, often no more than four per molecule and usually, less than three. It is generally preferable that the present compounds be unsubstituted but many of the substituted compounds are often of utility similar to those literally within the formulas given and therefore, are also useful. As has been illustrated by recitations of the specific compounds within the formulas given above, mixed salts may be employed as may be acid salts. Also, the salt-forming metal or other radical, if divalent or polyvalent, may be joined to both acid portions of the amino compound or a single salt-forming metal or other radical may be joined to two or more molecules of the acids of this invention.

The hydrocarbyl groups of R include both saturated and relatively slightly unsaturated groups. Thus, one or two double bonds per R are acceptable and are within the present invention, although it is preferred to em ploy alkyl groups as R. Of the alkyl groups, straight chain alkyls, terminally joined to the carbon to which the hydroxyl group is attached are highly preferred and are those described herein, unless indicated differently, although those alkyl groups which are not terminally joined also possess utility, as do various alkyl groups of non-linear structure. Thus, medially joined keryl (alkyl derived from kerosene) groups may be employed for R and there may also be used various polymeric materials, such as propylene tetramer and pentamer, a preferred form of which is such a mixture thereof as to average 13 carbon atoms per group.

R and R are preferably short chain alkylene, usually of l to 2 carbon atoms, but longer chain alkylenes and divalent hydrocarbyl radicals containing aromatic moieties are also useful to make detergent and softener products. Normally, the alkylenes will be present with a carbon content of the alkylene groups, R and R of four or less but in some instances as many as 9 carbon atoms may be found in such group to be good for making novel and useful surface active materials. When aromatic materials are employed, it is preferred that they be derivatives of benzene, usually with no more than two substituents on the benzene ring, in addition to joinder of the benzene ring to the rest of the present molecule.

X and Y, while they may be hydrogen, are preferably salt-forming ions. Of course, mixed substitution of hydrogen and salt forming ions is within the invention. The salts made are usually more stable and freer flowing than the acids and because the product is most frequently employed in alkaline solutions, it is therefore preferably in the salt form. Of the salt-forming ions, those which are monovalent are generally preferred, usually because of their greater water solubility, which is an important feature in the use of the present compounds in aqueous systems. However, even if water solubility is low, salts of low solubility can be employed as washing agents in other polar media and may be useful in an aqueous medium, especially if solvents or solubilizers are present.

The novel compounds of the present invention can be prepared by reacting a hydrocarbon-1,2-epoxide with an iminodicarboxylic acid. Such reactions are in accordance with the equation:

The reaction normally goes in aqueous solution wherein iminodicarboxylic acid, as the salt dissolved in the aqueous medium, is mixed well with an approximately stoichiometric proportion of the hydrocarbonl,2-epoxide.'Often, an additional solvent, such as alcohol, is employed, together with heat. The product is generally separated by conventional techniques, which may include treatments with a ketone to produce an oily precipitate, deoiling of such precipitate and conversion of the residue to a crystalline solid, which may be recrystallized from an alcohol to a desired purified product.

The iminodiacids and their salts are known compounds, as are the hydrocarbon epoxides. Methods for making such compounds from readily available starting materials are also known to those of skill in the art. Accordingly, they need not be described herein. Similarly, methods for making hydrocarbon-1,2-epoxides are known, and details thereof need not be given here.

In the reaction of although stoichiometric proportions are preferred, it is within the present invention to employ an excess of either reagent, depending upon the circumstances, with the usual excess not exceeding 50 percent and rarely exceeding 20 percent. Although the reaction may be effected at various temperatures, it is normally preferred to initiate it at approximately room temperature, e.g., 30C. Ordinarily, the iminodiacid reactant is dissolved in an aqueous medium and it is preferred to utilize deionized water for such medium. The proportion of water employed may be relatively small, and usually it is preferred to use from 25 to 200 percent of the total weight of the reactants. In any case, sufficient water is employed to dissolve the iminodiacid, and the epoxide, usually as a liquid, is admixed with the dissolved reagent. Such admixing may take from 10 seconds to 1 hour and during mixing the temperature of the reaction mixture is held within the mentioned room temperature range. After initial reaction, the temperatureis usually raised to from 50 C. to 110 C., depending upon the materials being reacted. The temperature most conveniently employed is the reflux temperature of the reaction mix. The reaction mixture is held at such temperature for a period of from about 1 hour to about 42 hours, after which it is considered that the reaction is complete. After that time, a one-phase system is found, from which the product may be obtained by precipitating with a suitable lower ketone, e.g., acetone, methyl ethyl ketone, diisopropyl ketone or other ketone having one to four carbon atoms in the alkyl groups thereof. Conversion to a solid crystal form may often be effected by treatment with a lower alcohol, such isopropanol or ethanol, after which purification may be effected by recrystallization from such solvent.

The products obtained are usually white or lightcolored solids, which in some cases may have a yellowish tinge. The solids may be somewhat hygroscopic but usually are sufficiently free-flowing to be employed, either by themselves or with other materials, as surface active agents or softeners for textiles.

The novel compounds produced are normally utilized in aqueous solution, either alone or with additives to produce improved detersive solutions or emulsions and to act as wetting agents. They are also used in such compositions to soften fabrics, especially cotton textiles, although they also soften other fabrics, such as wool and synthetics. In some processes the invented compounds usefully wash and soften textiles in a single operation. Such activity, wherein the softening agents are effective despite being added tothe wash water, rather than the rinse water, and wherein they themselves actto remove other substances from the fibers or laundry being washed, is considered to be unusual. Such softening effect appears to depend in significant part upon the substantivity of the invented compounds to the fibers. As a result of such dual utility, many of the present compounds are highly useful in combination detergent-softeners. The advantages of such compounds, as opposed to separate detersive and softening materials, have been recited previously.

The following examples are given to illustrate the invention but are not to be considered as limiting it. Unless otherwise stated, all parts given in the examples and elsewhere in the specification are by weight.

EXAMPLE 1 355 parts of iminodiacetic acid, as the disodium salt, I

3 minutes. Then 400 parts of normal butanol are added to the reaction mixture and it is refluxed for a period of 18 hours, with the temperature being in the range of -98C.

After the completion of refluxing, the temperature is allowed to drop and a single-phase system results. An oily residue is obtained from this phase by addition thereto of 500 parts of acetone. 65 parts of the oil are drawn off and are boiled for 1 hour with 500 parts of isopropanol. A crystalline solid settles out upon cooling to room temperature. This is separated by filtration and is recrystallized from an additional 250 parts of isopropanol. The recrystallized product'obtained is a white powder with a slight yellowish tinge. It appears to be slightly hygroscopic but flows relatively freely. It is obtained in nearly stoichiometric yield,with approximately 65 parts of purified product resulting.

When, in place of the disodium salt, the salt of iminodiacetic acid employed is the dipotassium salt, the di-ammonium salt, the di-triethanolamine salt or the mixed sodium-potassium salt, and the same general method for manufacture described aboveis employed, the corresponding N-(2-hydroxy-dodecyl)- iminodiacetates are obtained. Of course, the stoichiometrically equivalent amounts of such iminodiacetates will be employed in such reactions. Similar results are obtained when the acid form is employed.

The procedure of Example 1 is also followed, utilizing different iminodicarboxylates, such as iminodipropionic acid, disodium salt; iminodibutyric acid, dipotassium salt; iminoacetic-propionic acid,

mixed sodium, potassium salt; iminodibenzoic acid,

mono-triethanolamine salt; and iminodi-o-toluic acid, di-triethyl-amine salt, with the desired.N-(.2-hydroxyhydrocarbyl)-iminodi-carboxylates resulting. Corresponding products are obtained when the starting epoxides are n-decane-l ,2-epoxide; n-octane-1,2-epoxide; n-tetradecane-l ,2-epoxide; and n-hexadecane-1,2- epoxide. In some cases the times of reaction are extended or the temperatures are increased to promote reaction, whereas in other instances, a shorter time is needed and lower temperatures are employed, as will be evident to those of skill in the art. Also, the recovery methods utilized may be varied in specific situations to allow the production of the greatest proportion of the purest compounds.

EXAMPLE 2 The procedure of Example 1 is followed except that 480 parts of n-hexadecane-l,2-epoxide are employed instead of the 368 parts of n-dodecane-1,2-epoxide, and the refluxing is continued for 24 hours. At the end of that time, the reaction mixture has become water soluble and a single phase is produced. The desired product, N-(2-hydroxy-n-hexadecyl)-iminodiacetic acid, disodium salt, is recovered by the method described in Example 1. The product is a white powder of similar characteristics to that produced by the method of Example 1.

When the method of this example is followed, with the replacement of the hexadecane epoxide with other alkane-1,2-epoxides of 6 to 22 carbon atoms, corresponding iminocarboxylates are produced. In some cases, as with the longer chain epoxides, the reaction conditions must be varied, as by increasing temperature and using solvents and catalysts, to produce an economically feasible reaction rate. In most cases however, this is not necessary. Although it is normally desirable to utilize the linear alkyl epoxides, the cycloalkyl epoxides and the highly branched alkyl epoxides may also be employed, as may be the slightly unsaturated hydrocarbyl epoxides, such as the olefinic or dienic epoxides. The products resulting are useful surface active agents and in many cases possess exceptionally good textile-softening properties.

EXAMPLE 3 Although the products described in Example 1 and 2 possess general utilities as surface active agents, surface tension reducing agents, emulsifiers, detergents or softening agents for textiles, especially useful softening and detersive actions are noted for those compounds wherein R is of 12 to carbon atoms. An especially useful compound of this type is N-(Z-hydroxyhexadecyl)-iminodiacetic acid, disodium salt, which is representative of the best such compounds.

When tested for efficacy as a fabric softener, N-(2- hydroxyhexadecyl)-iminodiacetic acid, disodium salt, obtains a rating of 10+, indicating an excellent softening effect on cotton materials. The test is run using onehalf of a terrycloth towel in 3 gallons of 100 p.p.m. hardness water, at 120F. containing a detergent composition comprising 6.6 grams of sodium tripolyphosphate and two grams of N-(Z-hydroxyhexadecyl-iminodiacetic acid, disodium salt. After washing in a mini-basket of a General Electric Company automatic washing machine, the towel is rinsed in the usual way and is essentially freed of water. It is then dried and softness is rated, on a scale of l to 10, with 1 indicating a towel that is not soft and 10 indicating excellent softness. Using such a rating system, the towel washed with the detergent composition containing N-(Z-hydroxyhexadecyl)-iminodiacetic acid, disodium salt, as made following the procedure of Example 2 hereof, is given a rating of 10+. Softening effectiveness is also obtainable from the other new compounds of this invention in which R is of 12 to 20 carbon atoms.

The compounds of Examples 1 and Examples 2 are also evaluated for detersive properties. The results are indicated in Table 1.

TABLE 1 Spangler Soil Detergency Tests Rd (Soil Removal) N. B. tap 300 p.p.m. N. B. tap 300 p.p.m.

N(2-hydroxydodecyl)- iminodiacetic acid,

disodium salt 16.6 12.2 15.2 9.1 N-(2- hydroxyhexadecyl)- iminodiacetic acid,

disodium salt 15.5 11.8 13.1 9.3

The Spangler soil detergency tests are run using 15 percent of each of the mentioned compounds, 35 percent sodium tripolyphosphate and 50 percent sodium sulfate, to make a textile-softening and detergent composition. In these tests, the concentration of such washing preparation employed is 0.15 percent in water, which corresponds to the recommended usage of such materials in a home automatic washing machine. Three cotton percale swatches, each 3 inches by 6 inches, are first soiled with Spangler soil, which is a mixture of airborne and sebum soils. They are then washed in a Tergotometer evaluating washing machine, using waters of two different hardnesses, at two different temperatures, as indicated. After washing, the swatches are rinsed and are tested for whiteness, using a color difference meter. The comparison of readings, using the Rd scale, between the materials before and after washing, is made and the delta Rd is calculated. The greater the delta Rd, the more efficient is the soil removal and the better is the detergency obtained. Linear tridecyl benzene sulfonate, as the sodium salt, is usuallyemployed as a standard of comparison for detergency in this test.

From the data, as shown in Table 1, it is apparent that the novel compounds tested, which are representative of those made in accordance with this invention, as described above, are useful detergents. They are effective in hard water and water of medium hardness and in both hot and cold water, although they are most effective in ordinary city water of medium hardness, such as New Brunswick tap water, and wash better in hot water than in cold water. Similar results are obtained by use of the other iminodicarboxylates illustrated in the foregoing examples.

The present invention has been described in conjunction with various illustrations and embodiments thereof set forth in the specification. However, it is evident that equivalents may be substituted for the present compounds and procedural steps, without departing from the principles of this invention or the spirit thereof. Those of skill in the art will recognize equivalents and substitutes that are also within the scope of the present disclosure.

What is claimed is: l. A compound of the formula:

wherein R is alkyl of 12 to 20 carbon atoms, or alkenyl of 4 to 20 carbon atoms containing one or two ethylenic double bonds, R and R are alkylene radicals of l to 9 carbon atoms and X and Y which may be the same or different, are selected from the group consisting of hydrogen, alkali metal, ammonium, monoalkylamine, dialkylamine, trialkylamine, mono-alkanolamine, dialkanolamine, and trialkanolamine, in

which the alkyl and alkanol groups are of l to 4 carbon atoms.

2. A compound according to claim 1 wherein R is of 12 to 20 carbon atoms, R and R are of l to 4 carbon 

2. A compound according to claim 1 wherein R1 is of 12 to 20 carbon atoms, R2 and R3 are of 1 to 4 carbon atoms and are the same, and X and Y are the same.
 3. A compound according to claim 2 wherein R1 is a linear alkyl and R2 and R3 are of 1 to 2 carbon atoms.
 4. A compound according to claim 3 wherein R1 is of 12 to 14 carbon atoms, R2 and R3 are methylene and X and Y are alkali metal.
 5. A compound according to claim 4 wherein R1 is of 14 carbon atoms and X and Y are sodium. 